This invention relates to electronic keyboards. and particularly to the operation of keyboards used to enter text or data into a machine such as, for example, personal computers, computer terminals, and display-writers.
To the computer literate, the cursor is one of the most important characters displayed on the computer screen. The cursor is the blinking character which is moved around the screen and identifies where keyboard entries will be displayed and command inputs will be entered.
Movement of the cursor about the screen is achieved through a variety of keys on the keyboard. These include four arrow keys, one for each of the four directions--up, down, left and right. These keys move the cursor one character position at a time in the selected direction, although successive shifts of the cursor can be achieved by holding an arrow key down. The arrangement of the arrow keys varies from one type of machine to the next. In some cases, the arrow keys are arranged in a square; in others an inverted "T". The common arrangement for computer keyboards is a cross ("+"), with one arrow key at each point of the cross.
On computer keyboards, the arrow keys are part of the number pad on the righthand end of the keyboard, forming a cross on the keys bearing the numbers 2, 4, 6 and 8. Further keys adjacent to arrow keys provide for gross movement of the cursor. These include the "End," "Home," "PgUp," and "PgDn" keys, which also bear the numbers 1, 7, 9 and 3, respectively. Since the numbers 1 through 9 form a 3.times.3 square in this arrangement, the cross formed by the arrow keys has the number 5 key at its center, and the "End," "Home," "PgUp" and "PgDn" keys at the four corners, respectively.
Use of the arrow keys to move the cursor entails a risk of mistakes, since one can easily press a key adjacent to the one intended, whether it be another arrow key, a key outside the arrow key group, such as one of the gross movement keys, or the center (5) key in a cross arrangement. An operator who is working quickly may not notice the error until after having entered additional data. Once the error is noted, considerable time may have been lost and additional time will be needed to make the necessary corrections.
A variety of solutions to the problem are in existence. These solutions are various types of pointing devices which add circuits, parts and/or software to the system for use in place of the arrow keys. One such device is a "mouse," which is a small box-like device which is placed close by on the user's desk. The user pushes the mouse in the direction of the desired cursor movement. A disadvantage of this device is that it requires the user to move his or her hand away from the keyboard entirely to achieve cursor movement. Unfortunately, this device requires an appropriate jack on the computer for the connector of the mouse to plug into. In addition, it usually requires special circuitry in the computer, and special software to interpret the electrical signals which replace the normal arrow key signals.
Another such device is an electromechanical "joystick," This device has a lever which when moved in either right, left, forward or backward positions produces an equivalent movement of the cursor. This has the advantage of providing a more intuitive relationship between the action of the user's hand and the resultant effect. Like the mouse, however, the joystick requires an appropriate connector and jack as well as special circuitry and software.
Utility software does exist which interprets signals from such devices as the mouse and joystick. Such software is generally difficult to implement, however, and is often not supplied with the device. Furthermore, most application software is not organized to accept inputs from the utility software which interprets mouse or joystick activity, since application software is usually conditioned to accept only keyboard input and is virtually impossible for the end user to alter. This detracts considerably from the utility and versatility of these devices. A still further disadvantage of some joysticks or mouse devices is their inability to depress keys or perform functions like the "End," "Home," "PgUp" and "PgDn" functions.